Typically, mounted on a wheel axle are a pair of bearings, such as tapered roller bearings, used in rotation of the wheel. As one example, each roller bearing includes a bearing cone having an inner bearing race and a plurality of rollers, and an outer bearing race. Attached to one end of the wheel axle is a mechanism for setting the bearing adjustment.
A standard mechanism for setting the bearing adjustment includes a nut, a flat washer and a bearing lock washer interposed between the nut and the flat washer. The nut threadably engages the axle at one end securing the flat washer and the lock washer. In order to tighten the bearings, the nut is turned a predetermined number of revolutions until the rollers of the bearings exhibit a slight frictional drag when turning the wheel. Thereafter, the nut is untightened a small fraction of a turn until a locking tab of the bearing lock washer is engaged by bending into one of the many slots provided around the periphery of the nut.
With the above mechanism, automobile front wheels can operate successfully because the operating forces are sufficiently low. Many larger vehicles, such as heavy duty trucks and tractors, experience much higher forces and torques which cause the bearing cones to deflect or twist relative to the axle. This is turn causes wear of the axle and may ultimately cause failure of the bearings.
One solution to the above problem is currently achieved by carefully measuring the axial space between the bearing cones and providing a solid metal washer of slightly greater dimension which will cause the cones to be tightly clamped by the securing nut, thereby preventing relative movements and the resulting wear. However, the procedure to accomplish this selectively fitted washer is time consuming and expensive. It is particularly difficult when the bearing cones must be provided to have a diametral interference fit with the axle, often necessary as a part of the precautions to provide a tight assembly. In such cases, the outer bearing cone must be pulled off the axle with great difficulty, if the desired bearing fit is not achieved on the first trial assembly.
Therefore, a need still exists for a bearing setting procedure and apparatus which is easy to use and which will not cause damage to the axle or the bearings. A further need exists for a mechanism and procedure, which is relatively inexpensive and can be used in the continued production of numerous assemblies.